<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        class NewsType{
            static typeArr = ['娱乐','社会','经济','科技','军事'];

           static createOption(){  //创建新闻类别下拉列表框
                 let arr = this.typeArr;
                 let opt = '';
                 for(let i =0;i<arr.length;i++){
                    opt += `<option value="${arr[i]}">${arr[i]}</option>`;
                 }

                 document.write(`<select>${opt}</select>`);
            }
        }

        NewsType.createOption();
    </script>
</body>
</html>